The present invention is generally related cathode ray tube display control systems and more particularly to an improved man/machine interface and command entry device employed in such systems.
In many complex systems, such as a shipboard combat control system, wherein it may necessary to quickly select, actuate and then control a variety of offensive, defensive and operational subsystems under combat or other extreme conditions, one method of subsystem control is effected by creating a plurality of menus that are displayed on a cathode ray tube. Each of the menus displays the functional characteristics of a selected one of the subsystems, and the menus are stored in the memory of an associated computer. The menus are selectively called up and displayed on an output device, such as one or more cathode ray tubes. From the range of options displayed, an operator can then select one or more of these to enable and operate the selected subsystem in the manner defined by the menu option chosen. In many commercial computer systems, such functional selection is often done with a "mouse," but in many military applications, particularly in ships where violent pitch, yaw and roll motions can occur and in high performance aircraft, where such motions are compounded with cramped working spaces, the use of a mouse is often not practical.
In response to these problems, one current design for a subsystem/function selection system comprises a plurality of menu selection switches that are mounted in one or more rows along side of a cathode ray tube display. The system operator depresses one of the switches to first select and display the menu for a particular subsystem to be controlled and then depresses one or more other switches to select the function or functions to be performed from those displayed with the menu. This approach has two problems; one, it cannot be implemented in those situations that require the operator to be at more than arms distance from the display and the selector switches associated therewith; and second, particularly in horizontal summary displays, the operator often has to reach across the display to activate a particular switch and thus partially interfere with his view of the display, and the view of any others.
Accordingly, it is an objective of the present invention to provide a command entry device that eliminates the actuation problems associated with the mechanical switch system, while providing ease of use such as is provided by a mouse device.